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      1 /* Originally written by Bodo Moeller for the OpenSSL project.
      2  * ====================================================================
      3  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  *
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in
     14  *    the documentation and/or other materials provided with the
     15  *    distribution.
     16  *
     17  * 3. All advertising materials mentioning features or use of this
     18  *    software must display the following acknowledgment:
     19  *    "This product includes software developed by the OpenSSL Project
     20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
     21  *
     22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     23  *    endorse or promote products derived from this software without
     24  *    prior written permission. For written permission, please contact
     25  *    openssl-core (at) openssl.org.
     26  *
     27  * 5. Products derived from this software may not be called "OpenSSL"
     28  *    nor may "OpenSSL" appear in their names without prior written
     29  *    permission of the OpenSSL Project.
     30  *
     31  * 6. Redistributions of any form whatsoever must retain the following
     32  *    acknowledgment:
     33  *    "This product includes software developed by the OpenSSL Project
     34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
     35  *
     36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     47  * OF THE POSSIBILITY OF SUCH DAMAGE.
     48  * ====================================================================
     49  *
     50  * This product includes cryptographic software written by Eric Young
     51  * (eay (at) cryptsoft.com).  This product includes software written by Tim
     52  * Hudson (tjh (at) cryptsoft.com).
     53  *
     54  */
     55 /* ====================================================================
     56  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
     57  *
     58  * Portions of the attached software ("Contribution") are developed by
     59  * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
     60  *
     61  * The Contribution is licensed pursuant to the OpenSSL open source
     62  * license provided above.
     63  *
     64  * The elliptic curve binary polynomial software is originally written by
     65  * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems
     66  * Laboratories. */
     67 
     68 #ifndef OPENSSL_HEADER_EC_INTERNAL_H
     69 #define OPENSSL_HEADER_EC_INTERNAL_H
     70 
     71 #include <openssl/base.h>
     72 
     73 #include <openssl/bn.h>
     74 #include <openssl/ex_data.h>
     75 #include <openssl/thread.h>
     76 
     77 #if defined(__cplusplus)
     78 extern "C" {
     79 #endif
     80 
     81 
     82 /* Use default functions for poin2oct, oct2point and compressed coordinates */
     83 #define EC_FLAGS_DEFAULT_OCT 0x1
     84 
     85 struct ec_method_st {
     86   /* Various method flags */
     87   int flags;
     88 
     89   /* used by EC_GROUP_new, EC_GROUP_free, EC_GROUP_clear_free, EC_GROUP_copy: */
     90   int (*group_init)(EC_GROUP *);
     91   void (*group_finish)(EC_GROUP *);
     92   void (*group_clear_finish)(EC_GROUP *);
     93   int (*group_copy)(EC_GROUP *, const EC_GROUP *);
     94 
     95   /* used by EC_GROUP_set_curve_GFp, EC_GROUP_get_curve_GFp, */
     96   /* EC_GROUP_set_curve_GF2m, and EC_GROUP_get_curve_GF2m: */
     97   int (*group_set_curve)(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
     98                          const BIGNUM *b, BN_CTX *);
     99   int (*group_get_curve)(const EC_GROUP *, BIGNUM *p, BIGNUM *a, BIGNUM *b,
    100                          BN_CTX *);
    101 
    102   /* used by EC_GROUP_get_degree: */
    103   int (*group_get_degree)(const EC_GROUP *);
    104 
    105   /* used by EC_GROUP_check: */
    106   int (*group_check_discriminant)(const EC_GROUP *, BN_CTX *);
    107 
    108   /* used by EC_POINT_new, EC_POINT_free, EC_POINT_clear_free, EC_POINT_copy: */
    109   int (*point_init)(EC_POINT *);
    110   void (*point_finish)(EC_POINT *);
    111   void (*point_clear_finish)(EC_POINT *);
    112   int (*point_copy)(EC_POINT *, const EC_POINT *);
    113 
    114   /* used by EC_POINT_set_to_infinity,
    115    * EC_POINT_set_Jprojective_coordinates_GFp,
    116    * EC_POINT_get_Jprojective_coordinates_GFp,
    117    * EC_POINT_set_affine_coordinates_GFp,     ..._GF2m,
    118    * EC_POINT_get_affine_coordinates_GFp,     ..._GF2m,
    119    * EC_POINT_set_compressed_coordinates_GFp, ..._GF2m:
    120    */
    121   int (*point_set_to_infinity)(const EC_GROUP *, EC_POINT *);
    122   int (*point_set_Jprojective_coordinates_GFp)(const EC_GROUP *, EC_POINT *,
    123                                                const BIGNUM *x, const BIGNUM *y,
    124                                                const BIGNUM *z, BN_CTX *);
    125   int (*point_get_Jprojective_coordinates_GFp)(const EC_GROUP *,
    126                                                const EC_POINT *, BIGNUM *x,
    127                                                BIGNUM *y, BIGNUM *z, BN_CTX *);
    128   int (*point_set_affine_coordinates)(const EC_GROUP *, EC_POINT *,
    129                                       const BIGNUM *x, const BIGNUM *y,
    130                                       BN_CTX *);
    131   int (*point_get_affine_coordinates)(const EC_GROUP *, const EC_POINT *,
    132                                       BIGNUM *x, BIGNUM *y, BN_CTX *);
    133   int (*point_set_compressed_coordinates)(const EC_GROUP *, EC_POINT *,
    134                                           const BIGNUM *x, int y_bit, BN_CTX *);
    135 
    136   /* used by EC_POINT_point2oct, EC_POINT_oct2point: */
    137   size_t (*point2oct)(const EC_GROUP *, const EC_POINT *,
    138                       point_conversion_form_t form, unsigned char *buf,
    139                       size_t len, BN_CTX *);
    140   int (*oct2point)(const EC_GROUP *, EC_POINT *, const unsigned char *buf,
    141                    size_t len, BN_CTX *);
    142 
    143   /* used by EC_POINT_add, EC_POINT_dbl, ECP_POINT_invert: */
    144   int (*add)(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
    145              const EC_POINT *b, BN_CTX *);
    146   int (*dbl)(const EC_GROUP *, EC_POINT *r, const EC_POINT *a, BN_CTX *);
    147   int (*invert)(const EC_GROUP *, EC_POINT *, BN_CTX *);
    148 
    149   /* used by EC_POINT_is_at_infinity, EC_POINT_is_on_curve, EC_POINT_cmp: */
    150   int (*is_at_infinity)(const EC_GROUP *, const EC_POINT *);
    151   int (*is_on_curve)(const EC_GROUP *, const EC_POINT *, BN_CTX *);
    152   int (*point_cmp)(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
    153                    BN_CTX *);
    154 
    155   /* used by EC_POINT_make_affine, EC_POINTs_make_affine: */
    156   int (*make_affine)(const EC_GROUP *, EC_POINT *, BN_CTX *);
    157   int (*points_make_affine)(const EC_GROUP *, size_t num, EC_POINT * [],
    158                             BN_CTX *);
    159 
    160   /* used by EC_POINTs_mul, EC_POINT_mul, EC_POINT_precompute_mult,
    161    * EC_POINT_have_precompute_mult
    162    * (default implementations are used if the 'mul' pointer is 0): */
    163   int (*mul)(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
    164              size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
    165              BN_CTX *);
    166   int (*precompute_mult)(EC_GROUP *group, BN_CTX *);
    167   int (*have_precompute_mult)(const EC_GROUP *group);
    168 
    169 
    170   /* internal functions */
    171 
    172   /* 'field_mul', 'field_sqr', and 'field_div' can be used by 'add' and 'dbl'
    173    * so that the same implementations of point operations can be used with
    174    * different optimized implementations of expensive field operations: */
    175   int (*field_mul)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    176                    const BIGNUM *b, BN_CTX *);
    177   int (*field_sqr)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a, BN_CTX *);
    178   int (*field_div)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    179                    const BIGNUM *b, BN_CTX *);
    180 
    181   int (*field_encode)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    182                       BN_CTX *); /* e.g. to Montgomery */
    183   int (*field_decode)(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    184                       BN_CTX *); /* e.g. from Montgomery */
    185   int (*field_set_to_one)(const EC_GROUP *, BIGNUM *r, BN_CTX *);
    186 } /* EC_METHOD */;
    187 
    188 const EC_METHOD* EC_GFp_mont_method(void);
    189 
    190 struct ec_pre_comp_st;
    191 void ec_pre_comp_free(struct ec_pre_comp_st *pre_comp);
    192 void *ec_pre_comp_dup(struct ec_pre_comp_st *pre_comp);
    193 
    194 struct ec_group_st {
    195   const EC_METHOD *meth;
    196 
    197   EC_POINT *generator; /* optional */
    198   BIGNUM order, cofactor;
    199 
    200   int curve_name; /* optional NID for named curve */
    201 
    202   struct ec_pre_comp_st *pre_comp;
    203 
    204   /* The following members are handled by the method functions,
    205    * even if they appear generic */
    206 
    207   BIGNUM field; /* For curves over GF(p), this is the modulus. */
    208 
    209   BIGNUM a, b; /* Curve coefficients. */
    210 
    211   int a_is_minus3; /* enable optimized point arithmetics for special case */
    212 
    213   BN_MONT_CTX *mont; /* Montgomery structure. */
    214   BIGNUM *one; /* The value one */
    215 } /* EC_GROUP */;
    216 
    217 struct ec_point_st {
    218   const EC_METHOD *meth;
    219 
    220   /* All members except 'meth' are handled by the method functions,
    221    * even if they appear generic */
    222 
    223   BIGNUM X;
    224   BIGNUM Y;
    225   BIGNUM Z; /* Jacobian projective coordinates:
    226              * (X, Y, Z)  represents  (X/Z^2, Y/Z^3)  if  Z != 0 */
    227   int Z_is_one; /* enable optimized point arithmetics for special case */
    228 } /* EC_POINT */;
    229 
    230 EC_GROUP *ec_group_new(const EC_METHOD *meth);
    231 int ec_group_copy(EC_GROUP *dest, const EC_GROUP *src);
    232 
    233 int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
    234                 size_t num, const EC_POINT *points[], const BIGNUM *scalars[],
    235                 BN_CTX *);
    236 int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *);
    237 int ec_wNAF_have_precompute_mult(const EC_GROUP *group);
    238 
    239 /* method functions in simple.c */
    240 int ec_GFp_simple_group_init(EC_GROUP *);
    241 void ec_GFp_simple_group_finish(EC_GROUP *);
    242 void ec_GFp_simple_group_clear_finish(EC_GROUP *);
    243 int ec_GFp_simple_group_copy(EC_GROUP *, const EC_GROUP *);
    244 int ec_GFp_simple_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
    245                                   const BIGNUM *b, BN_CTX *);
    246 int ec_GFp_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
    247                                   BIGNUM *b, BN_CTX *);
    248 int ec_GFp_simple_group_get_degree(const EC_GROUP *);
    249 int ec_GFp_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
    250 int ec_GFp_simple_point_init(EC_POINT *);
    251 void ec_GFp_simple_point_finish(EC_POINT *);
    252 void ec_GFp_simple_point_clear_finish(EC_POINT *);
    253 int ec_GFp_simple_point_copy(EC_POINT *, const EC_POINT *);
    254 int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *, EC_POINT *);
    255 int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *, EC_POINT *,
    256                                                   const BIGNUM *x,
    257                                                   const BIGNUM *y,
    258                                                   const BIGNUM *z, BN_CTX *);
    259 int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *,
    260                                                   const EC_POINT *, BIGNUM *x,
    261                                                   BIGNUM *y, BIGNUM *z,
    262                                                   BN_CTX *);
    263 int ec_GFp_simple_point_set_affine_coordinates(const EC_GROUP *, EC_POINT *,
    264                                                const BIGNUM *x, const BIGNUM *y,
    265                                                BN_CTX *);
    266 int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *,
    267                                                const EC_POINT *, BIGNUM *x,
    268                                                BIGNUM *y, BN_CTX *);
    269 int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *, EC_POINT *,
    270                                              const BIGNUM *x, int y_bit,
    271                                              BN_CTX *);
    272 int ec_GFp_simple_add(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
    273                       const EC_POINT *b, BN_CTX *);
    274 int ec_GFp_simple_dbl(const EC_GROUP *, EC_POINT *r, const EC_POINT *a,
    275                       BN_CTX *);
    276 int ec_GFp_simple_invert(const EC_GROUP *, EC_POINT *, BN_CTX *);
    277 int ec_GFp_simple_is_at_infinity(const EC_GROUP *, const EC_POINT *);
    278 int ec_GFp_simple_is_on_curve(const EC_GROUP *, const EC_POINT *, BN_CTX *);
    279 int ec_GFp_simple_cmp(const EC_GROUP *, const EC_POINT *a, const EC_POINT *b,
    280                       BN_CTX *);
    281 int ec_GFp_simple_make_affine(const EC_GROUP *, EC_POINT *, BN_CTX *);
    282 int ec_GFp_simple_points_make_affine(const EC_GROUP *, size_t num,
    283                                      EC_POINT * [], BN_CTX *);
    284 int ec_GFp_simple_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    285                             const BIGNUM *b, BN_CTX *);
    286 int ec_GFp_simple_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    287                             BN_CTX *);
    288 
    289 /* method functions in montgomery.c */
    290 int ec_GFp_mont_group_init(EC_GROUP *);
    291 int ec_GFp_mont_group_set_curve(EC_GROUP *, const BIGNUM *p, const BIGNUM *a,
    292                                 const BIGNUM *b, BN_CTX *);
    293 void ec_GFp_mont_group_finish(EC_GROUP *);
    294 void ec_GFp_mont_group_clear_finish(EC_GROUP *);
    295 int ec_GFp_mont_group_copy(EC_GROUP *, const EC_GROUP *);
    296 int ec_GFp_mont_field_mul(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    297                           const BIGNUM *b, BN_CTX *);
    298 int ec_GFp_mont_field_sqr(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    299                           BN_CTX *);
    300 int ec_GFp_mont_field_encode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    301                              BN_CTX *);
    302 int ec_GFp_mont_field_decode(const EC_GROUP *, BIGNUM *r, const BIGNUM *a,
    303                              BN_CTX *);
    304 int ec_GFp_mont_field_set_to_one(const EC_GROUP *, BIGNUM *r, BN_CTX *);
    305 
    306 int ec_point_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
    307                                              EC_POINT *point, const BIGNUM *x,
    308                                              const BIGNUM *y, const BIGNUM *z,
    309                                              BN_CTX *ctx);
    310 
    311 void ec_GFp_nistp_points_make_affine_internal(
    312     size_t num, void *point_array, size_t felem_size, void *tmp_felems,
    313     void (*felem_one)(void *out), int (*felem_is_zero)(const void *in),
    314     void (*felem_assign)(void *out, const void *in),
    315     void (*felem_square)(void *out, const void *in),
    316     void (*felem_mul)(void *out, const void *in1, const void *in2),
    317     void (*felem_inv)(void *out, const void *in),
    318     void (*felem_contract)(void *out, const void *in));
    319 
    320 void ec_GFp_nistp_recode_scalar_bits(uint8_t *sign, uint8_t *digit, uint8_t in);
    321 
    322 const EC_METHOD *EC_GFp_nistp256_method(void);
    323 
    324 struct ec_key_st {
    325   int version;
    326 
    327   EC_GROUP *group;
    328 
    329   EC_POINT *pub_key;
    330   BIGNUM *priv_key;
    331 
    332   unsigned int enc_flag;
    333   point_conversion_form_t conv_form;
    334 
    335   CRYPTO_refcount_t references;
    336   int flags;
    337 
    338   ECDSA_METHOD *ecdsa_meth;
    339 
    340   CRYPTO_EX_DATA ex_data;
    341 } /* EC_KEY */;
    342 
    343 /* curve_data contains data about a built-in elliptic curve. */
    344 struct curve_data {
    345   /* comment is a human-readable string describing the curve. */
    346   const char *comment;
    347   /* param_len is the number of bytes needed to store a field element. */
    348   uint8_t param_len;
    349   /* cofactor is the cofactor of the group (i.e. the number of elements in the
    350    * group divided by the size of the main subgroup. */
    351   uint8_t cofactor; /* promoted to BN_ULONG */
    352   /* data points to an array of 6*|param_len| bytes which hold the field
    353    * elements of the following (in big-endian order): prime, a, b, generator x,
    354    * generator y, order. */
    355   const uint8_t data[];
    356 };
    357 
    358 struct built_in_curve {
    359   int nid;
    360   const struct curve_data *data;
    361   const EC_METHOD *(*method)(void);
    362 };
    363 
    364 /* OPENSSL_built_in_curves is terminated with an entry where |nid| is
    365  * |NID_undef|. */
    366 extern const struct built_in_curve OPENSSL_built_in_curves[];
    367 
    368 #if defined(__cplusplus)
    369 }  /* extern C */
    370 #endif
    371 
    372 #endif  /* OPENSSL_HEADER_EC_INTERNAL_H */
    373